All three projects in this P01 proposal will require the use of large amounts of a non commercially available glycolipid, alpha-galactosylceramide (alphaGC). On Project 1 (Savage) it will serve as a standard by which other glycolipids will be measured. On Project 2 (Teyton) alphaGC will be used primarily in efforts to generate crystals of CD1d-alphaGC complexes. On Project 3 (Bendelac) it will be employed in observing CD1d-TCR interactions. We have developed an efficient synthesis of alphaGC and will prepare the compound in small batches over the life of the project. We anticipate that the collective need will amount to 50 mg per year. If another glycolipid becomes a better standard, we will begin its preparation as well. All final compounds will be carefully purified and characterized using conventional analytical instrumentation and a rigorous biological assay of induced cytokine release.